title: Quantitative real-time PCR and phase specific serology are mutually supportive in Q fever diagnostics in goats.
abstract: This study presents results of quantitative pathogen detection by real-time PCR (qPCR) and phase-specific serology for complete Q fever diagnostics. For this, samples of 42 goats in total were taken during a Q fever outbreak. In the early phase of the Q-fever infection, 10(4)-10(8)Coxiella (C.) burnetii pathogens per vaginal swab and 10(2)-10(6)C. burnetii per ml milk were detected using quantitative real-time PCR (qPCR). Pathogen excretion decreased continuously within two months to less than 10(4) (vaginal swab) and 10(2) (milk) C. burnetii. At the end of the study there was a shift toward a 10 fold higher excretion of the pathogen via the genital tract and milk. At the start of the study, serological tests showed a dominance of the phase-2 antibody in 76% (22/29) of the goats in the MONA- (Multiple of Normal Activity) ELISA and 79% (23/29) in the IDEXX-ELISA, which was replaced by a phase-1 dominance in 85% (29/34) and 62% (21/34), of the animals respectively at the end of the study. Serum samples from 13 goats before lambing that excreted C. burnetii after lambing showed antibodies against phase 2 of 100% using MONA-ELISA and 77% in the IDEXX-ELISA. The most important diagnostic instrument for Q-fever infection in goats following birth is testing of vaginal swabs using qPCR. Phase-specific serology allows an estimation of possible pathogen excretion even before birth, as well as achieving valuable results for determination of the infection phase.
authors.affiliation: Chemisches und Veterinäruntersuchungsamt Stuttgart (Chemical and Veterinary Investigation Office Stuttgart), Schaflandstrasse 3/3, 70736 Fellbach, Germany. Electronic address: reinhard.sting@cvuas.bwl.de.
authors.forename: Reinhard
authors.initials: R
authors.lastname: Sting
authors.forename: Kerstin
authors.initials: K
authors.lastname: Molz
authors.forename: Werner
authors.initials: W
authors.lastname: Philipp
authors.forename: Friederike
authors.initials: F
authors.lastname: Bothe
authors.forename: Martin
authors.initials: M
authors.lastname: Runge
authors.forename: Martin
authors.initials: M
authors.lastname: Ganter
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood*; D016997:Coxiella burnetii / Q000235:genetics* / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D005260:Female; D015511:Goat Diseases / Q000175:diagnosis* / Q000276:immunology; D006041:Goats; D008892:Milk / Q000382:microbiology; D049590:Postpartum Period / Q000276:immunology; D011247:Pregnancy; D011778:Q Fever / Q000175:diagnosis / Q000276:immunology / Q000662:veterinary*; D060888:Real-Time Polymerase Chain Reaction; D013995:Time; D014621:Vagina / Q000382:microbiology
chemical_list: D000907:Antibodies, Bacterial
keywords: Coxiella burnetii; Goats; Phase-specific ELISA; Q fever; Quantitative real-time PCR